Carbon pile voltage regulator



Aug. 6, '1946. w. a. NEILD CARBON FILE VOLTAGE REGULATOR Filed March 8, 1944 INVENTOR. WillidlnG.Aild

BY W ATTGRNEY Patented Aug. 6, 1946 CARBON PILE'VOLTAGE' RE GULATOR William .G..Neild,,Warren P.0int, N J assignorto- Bendix Aviation. Corporation, Teterborn, N.v .I.,.. acorporation of Delaware Applicati'onMarch 8, 1944; Serial N 525,585

4 Claims. 1

Thisinvention relates to carbon pile electric regulators and is concerned primarily with the means provided for varying the pressure on the carbon pile.

A carbon pilevoltage regu1ator is ordinarily associated with a generator for the purpose of controlling the voltage. across the generator; Such a carbon pile regulator includes a carbon pile made up of a pluralityof carbon discs and" which is connected in series'withthe field of the generator. As the pressureon the carbon pilevaries, the strength of the field'is correspondingly varied and the generator regulated.

It is now common practice to employ magnetically actuated means for varying the pressure on thecarbon pile. Such magnetic-means. comprises a'magnetic'pot, including'a core, and Which pot houses the-usual solenoid coil. An armature which is disposed inoperative relation toone end of the carbon pile is'arranged to be affected by changes in the magnetic force generated by the solenoid. Inasmuch as this solenoidisconnected across the generator the strength of the magnetic field which it produces will vary in accordance with Variations in the voltage of the generator.

It is nowa well recognized and accepted fact that the magnetic force on the armature must 'be opposed in some manner, and this is usually accomplished by spring means. Thus, when the spring means and the. magnetic force actually balance, the armature is held immovable andthe resistance of the carbon pile remains constant. However; when the magnetic force changes, due to changes in the voltage, the armature is affected to be moved and thus vary the pressureon the carbon pile.

Inasmuch as the magnetic force which is effective on the armaturevaries inversely as the square of the distance across the gap between the armature and the core, it becomes necessary to provide spring means, the resistance of which will vary to a corresponding degree; to maintain the desired balance between the spring force and the magnetic force and leaveythe; regulating rangeundisturbed'.

An important object of this invention is the provision, in a carbon pile. electric regulatorof the character aforesaid, of novel spring means: for this purpose.

More in detail, the invention has as an. object the provision, in a carbon pile voltageregulator, ofv an armature, a magnetic pot, and a. substantially U-shaped. spring, one end of which is anchored. to the armature.- and the; other end, of which engages thatop. of the pot. In carrying this.- idea out, in a: practical embodiment, the in vention contemplates the use, of a. plurality of such springs which maybe equi-angularlyshaped about the circular-armature and which springs serve to maintain the armature in proper position.

An important phase; of the invention resides in the construction of these springs which are designed so thatthe resistancewhich they offer increases with movement of the armature towards. the magnetic pot, and. the degree of increase is substantially thesameas theincrease in magnetic force on the armature-'as-thelatter approaches the pot.

Yet another object of theinvention is the'provision, in a carbon pile voltage regulator of the character aforesaid, of novel spring means of' the type noted, which also includes instru-mentalities for properlypositioning the springs and armature carried thereby with respect to the pot. This end is achieved'by stamping each spring from a metal lank, so as to leave portions of the blank which donot=function assprings, but:si-mply as positioning means.

Various other more detailed objects and. advantages-of the invention such as arise in carrying out the above noted. thoughts in'a practical embodiment will in part become apparent and in part be hereinafter stated as the description of the invention proceeds.

The invention. therefore, comprises a carbon pile voltageregulator, including an armature-that is held in operative: position by a plurality of U- shaped springs. One end of each spring isanchored to. the armature, while the other end bears against the magnetic pot. Instrumentalties are also associated with the springs for maintaining them and the armature in proper position with. respect to the-pot.

For a full and more complete understanding of the invention, reference may behad to the following. description and drawing, wherein:

I. is aside View, partly-- in section and partly in elevation, of. those portions of a. carbon pile voltage regulatorwith which this invention is concerned;

Fig. 215 aplan viewofthe construction shown irrEig. 1.; and.

Fig. 3.isa. fragmentary showing similar. to Fig; l. of a modification.

Referring now to the drawing. wherein like reference characters. denote. corresponding arts, and first more; particularly to Figs. I and 2-, the carbon pileof a carbon. piler voltage regulator is shown. at. H); While; the; invention is described aeoasie as applied to a voltage regulator, it will be understood that it might just as well be applied to any electric regulator which embodies, as an essential element, a variable resistance. Also, while the resistance which is varied is illustrated and described as a carbon pile, it could obviously take the form of a pile of discs of any material such as a metal having the properties which would suit it to this particular use.

The pile Iii is made up of a plurality of carbon discs in accordance with customary practice. The function of the regulator is to vary the pressure on the pile iii. For this purpose an armature ll carries an abutting member 52 which engages with, or is connected to, one end of the pile H].

In the form of the invention illustrated in the drawing, the pile iii, armature H and magnetic pot about to b described, are illustrated as circular, although this is intended to be no limitation on the invention. Obviously, the circular formation could be deformed without departing from the spirit of the invention.

A magnetic pot is referred to in its entirety by the reference character P and is shown as comprising a cylindrical wall I3, which carries a top wall it and a bottom wall i5. It will be noted that the cylindrical wall i3 projects above the top wall [4 a slight distance to provide a peripheral flange it.

The top wall M is formed with the usual central Opening ll, and a cylindrical core 88 upstands from the bottom wall 15 and has its top end located in the opening H. A solenoid indicated at S is positioned in the pot P about the core I8.

The armature l i is held in position by a plurality of spring assemblies, each of which is of substantially the same construction as the other. Thus, only one of these spring assemblies is herein described for the purposes of this specification. Each spring assembly comprises a base l9, from which is struck a tongue or leaf Zil that is bent up and over into U-shaped formation. The free extremity of each tongue 26! is anchored to the upper face of the armature H in any preferred manner, as by the screw fastening elements shown at 2 i.

It will be noted that the bases 20 conform in shape to the cylindrical formation of the pot P, and their outer peripheral edges engage the flange it. Thus, each spring assembly is positioned and serves to maintain the armature H in proper position.

It is particularly important to note that the spring device thus described provides a convenient and novel means for mounting the armature which device is of such simplicity in construction as to be readily adapted for manufacture and installation at low cost.

In the operation of the device, the tongue spring members are so arranged that as the armature it approaches the top of the core E8, the magnetic force of the latter varies inversely as the square of the distance between the armature and the top of the core. The resistance offered by the springs 20 must Vary commensurate with these changes in the magnetic force. The springs being of the cantilever typ may be so designed as to have this property.

While the operation of the above-described mechanism is believed to be obvious, it may be briefly outlined by noting that the solenoid is connected across the generator, while the carbon pile I is in series with the field of the generator. Normally, the magnetic force offered by the magnetic pot P is counter-balanced by the springs 20, and the armature is held immovable to maintain constant the resistance of the pile ii]. As the voltage across the generator varies, there is a corresponding change in the coils of the solenoid S to effect a change in the magnetic force. The armature ll is moved by this change in the magnetic force, and thus the pressure on the carbon pile I0 is varied, which in turn varies the field strength of the generator.

Referring now more particularly to Fig. 3, where there is illustrated a modified form of the invention in which provision is made for temperature compensation, at thermostatic ring 22, which may be of the well known bimetal structure, is positioned on the top I4 of the magnetic pot about the opening ll.

A washer 23 may engage the ring 22, and this washer 23 carries U-shaped springs which are anchored to the armature i I in the manner above described. It is evident that the conical formation of the bimetallic ring 22 provides for a change in the relative position of the armature assembly coincident with variations in temperature.

While two embodiments of the invention are hereinbefore set forth, it is to be clearly understood that the invention is not to be limited to the exact constructions illustrated and described, because various modifications of these details may be provided in putting the invention into practice within the purview of the appended claims.

What is claimed is:

1. In a carbon pile electric regulator including a carbon pile and a magnetic pot having a top surrounded by a peripheral flange, an armature assembly for regulating said carbon pile, comprising an armature, a base plate of circular shape positioned Within said peripheral flange and adjacent said top and flange, a series of tongue portions formed integral with said plate and projecting therefrom in a U-shaped formation, said U-shaped tongue portions extending radially inward of said base plate and having the free ends thereof fastened to said armature so as to flexibly support said armature relative to said carbon pile and magnetic pot.

2. In a carbon pile electric regulator including a carbon pile and a magnetic pot having a top surrounded by a peripheral flange, an armature assembly for regulating said carbon pile, comprising an armature, a base plate of circular shape positioned within said peripheral flange and adjacent said flange, a series of tongue portions formed integral with said plate and projecting therefrom in a U-shaped formation, said U-shaped tongue portions extending radially inward of said base plate and having the free ends thereof fastened to said armature so as to flexibly support said armature relative to: said carbon pile and magnetic pot, and temperature responsive means for adjustably positioning said base plate with relation to the top of said magnetic pot.

3. In a carbon pile electric regulator including a carbon pile and a magnetic po-t having a top surrounded by a peripheral flange, an armature assembly for regulating said carbon pile, comprising an armature, a base plate of circular shape positioned within said peripheral flange and adjacent said flange, a series of tongue portions formed integral with said plate and projecting therefrom in a U-shaped formation, said U-shaped tongue portions projecting inwardly of said base plate, screw members for adjustably fastening the free ends of each of said tongue portions to said armature so as to flexibly support said armature relative to said carbon pile and magnetic pot.

4. In a carbon pile electric regulator including a carbon pile, a magnetic element, and an armature assembly for regulating said carbon pile,

tongue members formed integral with said base plate and projecting therefrom in a substantially U-shaped formation, each of said tongue members having end portions positioned in spaced relation to said base plate and extending inward of said base plate, and means fastening each of the end portions of said tongue members to said armature so as to flexibly support said armature in relation to said carbon pile and magnetic comprising an armature, a base plate carried at 1 element.

one end of said magnetic element, a plurality of WILLIAM G. NEILD. 

